Automated determination of glucose in serum or plasma by a direct o-toluidine procedure.

A LDOHEXOSES REACT WITH o-toluidine in the presence of glacial acetic acid to produce a green color, which follows Beer’s law over a wide range of concentrations. This reaction is relatively selective for glucose. An improvement in manual procedures involving this reaction (1, 2) was reported by Feteris (3), who determined glucose directly on serum without deproteiization. She also improved the sensitivity of the o-toluidine reagent by adding thiourea. An automated o-toluidine method for glucose requiring dialysis was reported by Zender (4). This paper reports an automated procedure for determining glucose in serum or plasma, without dialysis, using an o-toluidine reagent. The new automated procedure is compared with the manual method of Feteris (3).